This invention relates generally to materials grinding and processing machines and, more particularly, to systems and methods for changing sizing screens in such machines.
Waste disposal, and in particular, the disposal of construction, demolition and similar debris, is a serious and growing problem. Although such debris consists principally of relatively clean, non-hazardous materials such as pavement, bricks, lumber, shingles, glass and the like, the shear bulk of such materials can make their disposal a challenge. Accordingly, various machines have been developed for grinding, shredding and otherwise reducing such materials to a more compact and easily handled form.
In one form of materials processing machine, such as that shown in U.S. patent application Ser. No. 07/778,322, filed Oct. 17, 1991, now U.S. Pat. No. 5,344,088, entitled "Materials Grinder" and commonly owned by the assignee hereof, improved grinding and shredding action is achieved through use of a sizing screen concave which positions a sizing screen adjacent a rotary hammer or drum to further process partially comminuted material. Although effective, the sizing screen is subjected to terrific punishment and must be reversed and replaced from time to time. Different forms of sizing screens can be installed to vary the final product size. For these, reasons, it is necessary to change sizing screens several times in the life of a materials processing machine.
Typically, several hours were required to change a sizing screen in a materials processing machine of the type shown in U.S. patent application Ser. No. 07/778,322. Not only do labor costs associated with changing a sizing screen become significant when considerable time is required to change the screen, but the machine is out of service and, hence, unproductive during this time. There is a need, therefore, to reduce and minimize the time required to change sizing screens in a materials processing machine.